Ministry of Rural Development Government of India Quality Assurance Handbook for Rural Roads Volume-I Quality Management System and Quality Control Requirements May 2007 National Rural Roads Development Agency

Quality Assurance Handbook for Rural Roads has been developed by: Indian Roads C ongress Kamakoti Marg, Sector-6, R.K. Puram, New Delhi-110022 All Rights Reserved Published by National Rural Roads Development Agency, Minist ry of Rural Development, Government of India, New Delhi Copies can be obtained from National Rural Roads Development Agency Ministry Of Rural Development, Government Of India #5th, Floor, 15 NBCC Tower, Bhikaji Cama Place, New Delhi-110066 Ph.: 011-26716930, 011-41000472

QUALITY ASSURANCE HANDBOOK FOR RURAL ROADS VOLUME I CONTENTS PAGE NO. FOREWORD PREFACE ABBREVIATIONS CHAPTER 1 INTRODUCTION CHAPTER 2 QUALITY MANAGEMENT SYSTEM CHAPTER 3 Section 100 105 108 109&110 114 Section 200 201& 20 2 Section 300 301 302 303 304 306 307 Section 400 401 QUALITY CONTROL OF WORKS G ENERAL Construction Equipment Setting Out Public Utilities and Environment Metho dology & Sequence of Work SITE CLEARANCE Site Clearance EARTHWORKS Embankment Co nstruction Earthwork in Cutting Subgrade Construction Rock Cutting Flyash Embank ment Construction Surface Drains GRANULAR SUB-BASES, BASES & SURFACINGS Granular Sub-Base III 1 to 5 7 to 10 13 to 15 19 23 to 38 41 to 79

402 403 404 405 406 407 408 409 410 411 412 413 Section 500 501 502 503 504 505 506 507 508 509 510 512 Section 600 Section 700 Section 800 Section 900 Gravel/Soil-Aggregates Base & Surface Course Lime Treated Soil for Improved Subg rade/Sub-base Cement Treated Soil Sub-Base/Base Water Bound Macadam Sub-Base/Bas e/Surfacing Wet Mix Macadam Base Shoulder Construction Local Materials for Road Construction Lime-Flyash Stabilised Soil Sub-Base Industrial Wastes for Road Con struction Crusher-Run Macadam Base Brick Soling Stone Set Pavement BITUMINOUS CO NSTRUCTION Preparation of Surface Prime Coat Over Granular Base Tack Coat Bitumi nous Macadam Built-Up Spray Grout Modified Penetration Macadam Surface Dressing 20 mm Thick Premix Carpet Mix Seal Surfacing Seal Coat Modified Bitumen BRICK WO RK FOR STRUCTURES STONE MASONRY FOR STRUCTURES CONCRETE FOR STRUCTURES FORMWORK AND SURFACE FINISH FOR STRUCTURES STEEL REINFORCEMENT IV 83 to 120 123 to 128 131 to 136 139 to 147 151 to 154 157 to 159 Section 1000

Section 1100 Section 1200 Section 1300 Section 1400 Section 1500 1501 1502 1503 1504 Section 1600 Section 1700 PIPE CULVERTS RCC SLAB CULVERTS AND MINOR BRIDGES PROTECTION WORKS AND DRAINAGE CEMENT CONCRETE CAUSEWAY CEMENT CONCRETE PAVEMENT Plain Cement Concrete Pavement Roller Compacted Concrete Pavement Rectangular Concrete Block Pavement Interloc king Concrete Block Pavement HILL ROAD CONSTRUCTION TRAFFIC SIGNS, MARKINGS & OT HER ROAD APPURTENANCES MAINTENANCE Maintenance of Earthworks Maintenance of Bitu minous Surface Road Maintenance of Gravel Road Maintenance of WBM Road Maintenan ce of Culverts and Causeways 163 to 166 169 to 177 181 to 185 189 to 193 197 to 215 219 to 222 225 to 227 231 to 241 Section 1900: 1901, 1902 & 1903 1904 1905 1906 1908,1909 1910,11,12,13,14 &15 Maintenance of Road Signs, Markings & Appurtenances CHAPETR 4 QUALITY MONITORING BY NATIONAL/STATE QUALITY MONITIORS 243 to 274 Appendices Appendix-1 Appendix-2 Handfeel Tests Guidelines for Appropriate Technology for Rural Road Construction List of IRC Publication List of MORD and MOSRTH Publications VOLUME II App. 1/1 to 1/8 App. 2/1 to 2/2 Appendix-3 Appendix-4 App. 3/1 to 3/7 App. 4/1 to 4/2 EQUIPMENT AND PROCEDURES FOR TESTS V

FOREWORD Focus on quality has been a singular feature of the Pradhan Mantri Gram Sadak Yo jana (PMGSY) right from its inception. In fact, the report of the National Rural Roads Development Committee, which formed the conceptual basis of this programm e, specifically highlighted the need for inbuilt quality assurance mechanisms, a s a first step towards institutionalizing quality assurance system in the progra mme implementation, a quality control handbook for rural roads was brought out i n 2002 by the National Rural Roads Development Agency (NRRDA) covering various t ests to be conducted, frequency of these tests and details of the test procedure s. However, at that time separate specifications were not available for the low volume rural roads. In 2004 the Ministry of Rural Development brought out Specif ications For Rural Roads, which was published by the Indian Roads Congress (IRC) . Following this technical experts as well as the programme managers felt that t here was a consequential need to revise the Quality Control Handbook. Accordingl y, the work of revising the handbook was entrusted to the IRC which constituted a group of experts headed by Shri S. C. Sharma, former Director General (Road De velopment) and Additional Secretary, Ministry of Road Transport and Highways. Th e other members of this expert group were Shri D. P. Gupta, Dr. V. M. Sharma, Dr N. B. Lal, Shri M. V. B. Rao, Shri G. S. Khinda and Shri S. P. Singh. This revi sed version of the quality Assurance Handbook for rural roads does not restrict itself to quality control only. It has widened the scope by adopting the princip les of quality assurance as laid down by the IRC. Volume-I of this handbook deal s with the quality management system and quality control requirements and Volume -II covers the equipments and test procedures. Quality monitoring of the project s through independent, third party monitors at the State level as well as at the Central level has also been dealt with in Volume-I. Unlike the earlier practice of seeking quality control only during construction, this handbook recommends e xercising quality control at three stages at the stage prior to construction, du ring the construction phase and quality checks by the field engineers after comp letion of each stage of construction, which is termed as stage passing. A number o f carefully thought out Dos and Donts for each activity and item of work have also b een prescribed for the guidance of users. In its present form, this handbook inc orporates valuable suggestions and recommendations which were received during a workshop which was specifically organized to review the draft on April 16-17, 20 07 at Central Road Research Institute, New Delhi. I would like to express my sin cere appreciation to the IRC, the members of the expert group for their painstak ing efforts, to all the members of the peer review group for their meticulous an d methodical scrutiny, and to all the participants of the national workshop whic h was held in April 2007 for their valuable contributions. I do believe that in the implementation of PMGSY in substantial measure. (J. K. Mohapatra) Joint Secretary (RC) Ministry of Rural Development & Director General National Rural Roads Development Agency V

PREFACE A good road network has an important bearing on the economic growth of the count ry. Rural Connectivcity is perceived as one of the major component in increasing the agricultural output and earning capacity of the rural population. There is a marked improvement in quality of life by way of better educational facilities, improved health services, improved attendance by the school teachers as well as students. Accessibility also provides improvement in governance and provision o f other facilities like post offices, access to police in case of emergencies an d other communication system like telephones. As a measure of poverty reduction, Government of India has launched Pradhan Mantri Gram Sadak Yojana (PMGSY) in De cember, 2000. The management systems developed for implementation of the program me are centered on quality and the guidelines clearly prescribe to provide good all-weather connectivity to target habitations. Construction of quality roads re quires concerted efforts on many fronts, therefore, a three tier quality mechani sm has been operationalized under the programme. The first tier provides for inhouse quality control, wherein, the Programme Implementation Unit (PIU) is requi red to control the quality of work through performing mandatory tests for the ma terial and workmanship. The second and third tier of quality mechanism provides for monitoring of quality by the independent quality monitors at the State Level and at the National Level. The PMGSY Guidelines provides that the NRRDA will is sue general guidelines on quality control and prescribe a Quality Control Hand B ook to regulate the quality control process at works level. Accordingly, a Quali ty Control Hand Book was brought out in 2002. Based on feedback received from St ates, executing agencies and other organizations, it was felt that handbook may also contain details about the tests involved in construction of cross drainage works, rigid and semi-rigid pavements and protection works etc. The Rural Roads Specifications provide for mandatory testing of material and workmanship and fee dback of the field formations regarding the frequency of tests indicated that th ere is a scope to revisit these frequencies. Therefore, National Rural Roads Dev elopment Agency decided to review the Quality Control Hand Book and the work of review was entrusted to Indian Roads Congress (IRC). The IRC was requested to re view the content of Quality Control Hand Book with a view to include details abo ut all the tests required for construction of roads and related cross drainage w orks etc. It was also requested that the IRC may review the prescription of freq uency of tests and examine whether the concept of stage passing may be introduce d to ensure clear accountability. The IRC constituted Expert Group headed by Shr i S. C. Sharma, Former Director General, Ministry of Road Transport and Highways . The Expert Group prepared the contents of the Handbook and based on the level of work and its utility, the title of the handbook was decided as Quality Assuran ce Hand Book for Rural Roads. The drafts of Quality Assurance Hand Book were revi ewed in a series of meetings and deliberations by a Peer Review Committee, const ituted by NRRDA as below: Prof. C. E. G. Justo, Emeritns Fellow, Bangalore Unive rsity Chairman Shri Prabha Kant Katare, Director (Projects-III), NRRDA Convener MEMBERS Dr. Ashok Kumar, Rural Roads Specialist, World Bank Dr. Praveen Kumar, I ndian Institute of Technology, Roorkee VII

Shri H. L. Meena, Chief Engineer PWD, Rajasthan Engineer-in-Chief, PWD (R&B), Na galand Shri V. V. Gulati, Former Chief Engineer P.W.D, Uttarakhand. Shri Vidya S agar Singh, Former Chief Engineer, U.P.P.W.D. Shri H. K. Srivastava, Director (P rojects-I), NRRDA Dr. B. P. Chandrasekhar, Director (Technical), NRRDA Shri S. B aliga, Director (Projects-II), NRRDA State Quality Coordinator (PMGSY), MPRRDA, Madhya Pradesh State Quality Coordinator (PMGSY), HPPWD, Himachal Pradesh The su ggestions of members of Peer Review Committee and officers of NRRDA on the draft Hand Book were incorporated and final draft document was prepared. A National W orkshop on Quality Assurance Hand Book was organized on 16-17th April, 2007 at C RRI to review of the contents of Draft Handbook. Dr. Subas Pani, Secretary, Mini stry of Rural Development inaugurated the Workshop and in addition to his valuab le guidance about internalizing the quality consciousness, he mentioned that eno rmous efforts have been made in preparation of the Hand Book and it should be us ed extensively by the field officers engaged in implementation of PMGSY. It was suggested by him that the Quality Assurance Hand Book should be made available o n the Programme Website, so that the officers, contractors and other constructio n agencies can have easy access to the provisions of quality assurance. The work shop was attended by representatives of almost all the States and experts. A num ber of valuable suggestions and comments made at the Workshop were suitably inco rporated in the present form of Quality Assurance Hand Book. Volume I of the Han dbook covers quality management system and details about quality control require ments. The revised frequency of tests and requirements about stage passing in fo rm of quality control checks have been elaborated in this Volume. Volume II give s detailed description about equipment and test procedures. I would like to expr ess my sincere gratitude to members of Expert Group, members of Peer Review Comm ittee and Shri R. S. Sharma, Former Secretary, IRC whose pains taking efforts ha ve brought out this wonderful document. I would also like to express my sincere appreciation to the efforts made by Shri V. K. Sinha, Secretary General IRC, off icers and other staff of IRC in bringing out this handbook in the present form. I thankfully acknowledge the contribution made by the participants of the worksh op organized at CRRI in April, 2007. The document of this nature cannot remain s tatic with continuous upgradation of technology. User of this handbook would be the best judge of the deficiencies, if any still left in the document. We would greatly value the feedback and suggestions in this regard to keep this document updated. I am confident that this document would serve its intended purpose. (Prabha Kant Katare) New Delhi May, 2007 VIII Director (Projects) & Chief Quality Coordinator National Rural Roads Development Agency

ABBREVIATIONS AE AIV BOQ CBR CD CRMB cum EE g GBFS GSB GTS h IS JE kg km kN l m MB ml mm MORD MORTH MPa : : : : : : : : : : : : : : : : : : : : : : : : : : Assistant Engineer Aggregate Impact Value Bill of Quantities California Bearing Ratio Cross-Drainage Crumb Rubber Modified Bitumen Cubic metre Executive Enginee r Gram Granulated Blast Furnace Slag Granular Sub-Base Grand Triangulation Surve y Hour Indian Standard Junior Engineer Kilogram Kilometre Kilo Newton Litre Metr e Modified Binder Millilitre Millimetre Ministry of Rural Development Ministry o f Road Transport & Highways Ministry of Shipping, Road Transport & Highways Mega Pascal IX MOSRTH :

MPM MS NRRDA NQM OMC PMB RMB RS SQC SQM sqm SS UCS WBM WMM : : : : : : : : : : : : : : : Modified Penetration Macadam Medium Setting National Rural Roads Development Age ncy National Quality Monitor Optimum Moisture Content Polymer Modified Bitumen R ubber Modified Bitumen Rapid Setting State Quality Coordinator State Quality Mon itor Square metre Slow Setting Unconfined Compressive Strength Water Bound Macad am Wet Mix Macadam X

Quality Assurance Handbook for Rural Roads CHAPTER 1 INTRODUCTION 1. BACKGROUND 1.1 A major rural road programme known as Pradhan Mantri Gram Sadak Yojana (PMGS Y) is being implemented since December 2000 by the Government of India through t he Ministry of Rural Development (MORD). The National Rural Roads Development Ag ency (NRRDA), working under the aegis of the MORD, provides the overall administ rative, technical and programme support to the states in the execution of works. The scheme envisages construction of good quality all-weather roads to provide connectivity to habitations with a population of 500 and above (250 and above in case of hills, deserts and tribal areas). Emphasis is being laid on planning, d esign, construction and maintenance of rural roads based on sound engineering pr inciples, which conform to specifications, codes of practice and manuals of the Indian Roads Congress. A comprehensive document, IRC:SP:20 entitled Rural Roads Manual has been brought out in 2002 for adoption in case of all rural roads incl uding works being carried out under the PMGSY programme. Subsequently, the NRRDA brought out its own Handbook on Quality Control for Road Works and Operations M anual for PMGSY works. A detailed Book of Specifications for Rural Roads and Sta ndard Data Book for Analysis of Rates have also been prepared and published thro ugh the Indian Roads Congress. A strong technical underpinning has been given so that roads taken up under this programme conform to the MoRD specifications. 1. 2 The Government of India have recently reviewed the progress of the PMGSY and o ther schemes relating to rural development and have decided to undertake a bold initiative of building infrastructure in rural areas under an umbrella programme , known as Bharat Nirman. The PMGSY is one of the six components of the Bharat Nir man and the following targets have been set: (i) (ii) (iii) Provide all-weather connectivity to habitations of population above 1000 (500 in case of hills, dese rts and tribal areas). The task would involve connectivity to 66,802 habitations . The work involves construction of over 140,000 km of new roads and upgradation of over 190,000 km of existing rural roads at an estimated cost of Rs 48,000 cr ore. 2. QUALITY ASSURANCE 2.1 A three-tier quality management mechanism has been operationalized under PMG SY for ensuring that the quality of assets created conform to the prescribed sta ndards. The first tier of quality management mechanism is in-house quality contr ol at the level of the executing agencies whereas the second tier provides for q uality monitoring through independent State Quality Monitors (SQM). Monitoring b y independent National Quality Monitors (NQM) constitutes the third tier of this arrangement. Under this arrangement, it is the responsibility of the State Gove rnment to operationalize the first and the second tiers of the quality managemen t structure. 1

1. Introduction It is proposed to widen the scope of quality control by including the principles of Quality Assurance laid down by the Indian Roads Congress in their guidelines on quality systems for roads (IRC:SP:572000) and for bridges (IRC:SP:47-1998). A Total Quality Management approach is envisaged. The concept of Total Quality M anagement (TQM) as defined by ISO reads as TQM is a management approach of an Org anisation, centered on Quality, based on participation of all its members and ai ming at longterm success through customer satisfaction, and benefits to all the members of the Organisation and the Society. In fact the TQM is a management stra tegy aimed at embedding awareness of Quality in all organisational processes. Th e TQM concept in the context of Rural Roads suggests that quality has to be seen as the basic policy starting from conception till the operation and management of Rural Road assets. The objective of the PMGSY is to provide Good All Weather R oads and the implementation strategies of the programme are therefore, centered o n the word Quality. 2.2 Class of Quality Assurance (QA) for Rural Roads: Four clas ses of Quality Assurance are prescribed as under: Quality Assurance 1. 2. 3. 4. Nominal QA Normal QA High QA Extra High QA Q1 Q2 Q 3 Q4 Class For rural roads, Class Q 2 may be adopted. However, for a particular project or even for particular activities, decision regarding upgradation of QA class could be taken by the Project Implementation Unit keeping in view the level of qualit y and the level of control expected beyond Class Q 2. The quality assurance requ irements in respect of materials and workmanship to be achieved during execution are described against each item of road and bridge work in relevant Sections. 2 .3 For day-to-day reference of the Engineers in the field and the Contractors en gaged in construction of rural roads, this Handbook on Quality Assurance has bee n prepared drawing heavily on the following sources: (i) (ii) (iii) (iv) Specifi cations for Rural Roads, MoRD (2004). Rural Roads Manual IRC:SP:20-2002. Handboo k on Quality Control: Road Works NRRDA (2002). Hill Road Manual: IRC:SP:48-1998. The frequency of tests has been further rationalized and NRRDA will bring out th e necessary modifications in MoRD Specifications for Rural Roads. The quality co ntrol requirements prescribed in the Book will be mandatory for all PMGSY works. This book would also serve as a useful reference to the State Technical Agencie s, State-level Quality Control Units, and National Quality Monitors. 3. 3.1 (i) QUALITY CONTROL The Quality Control on Rural Roads and Cross-Drainage Works shall be exercised a s follows: Quality Control Tests on Materials before incorporation in the Works: 2

Quality Assurance Handbook for Rural Roads All materials before incorporation in the work shall be tested by the Contractor for the tests indicated under Tests to be carried out Prior to Construction. The tests shall be carried out from each source identified by the Contractor. The te st samples shall be representative of the material available from the source. An y change/variation in the quality of material with depth of strata shall be repo rted. Important tests like the Moisture-Density relationship (Proctor Compaction ), Aggregate Impact Value, Plasticity Index, CBR and any other tests specified b y the Engineer shall invariably be carried out in the presence of a representati ve of the Engineer, who will not be below the rank of Junior Engineer. The test results shall form the basis for approval of the source and the material for inc orporation in the work and shall be approved by the Engineer. For manufactured i tems, however, such as concrete pipes, elastomeric bearings etc, a test certific ate obtained by the Manufacturer from an approved Test House shall be accepted. (ii) Quality Control Tests During Construction: During execution of the work, qu ality control for workmanship and ensuring conformance to specifications shall b e exercised on the basis of the tests indicated under Field Quality Control Tests During Construction. The tests shall be carried out by the Contractor independen tly or in the presence of Employers representative, normally a Junior Engineer, w hen available at site or where association of the Employers representative in tes t is prescribed. The Junior Engineer shall record the results in his own handwri ting. The Contractor shall be fully responsible for all the tests carried out fo r the work. The Assistant Engineer/Executive Engineer during their site visits s hall have a few tests carried out in their presence and sign the Quality Control Register. (iii) Stage Passing: Supervisory officers of the level of AE and EE s hall exercise quality control checks and certify the work of various stages on t he basis of tests and their frequencies indicated under Quality Control Checks. Th e officer certifying the work at various stages as prescribed shall be responsib le for the quality and quantity of the work certified by him. (iv) Procedure to form part of the Contract: The prescribed tests, frequencies and the procedure f or stage passing by Supervisory Officers shall be mandatory and shall form part of the Contract. 3.2 Random Checks Where random checking has been recommended, the procedure to be adopted for rand om checking shall be as follows: (i) The complete section to be checked shall be divided into ten sub sections of equal length viz. 0-100 m, 100-200 m, 200-300 m. Of these, only two sub-sections shall be selected for carrying out tests by d raw of lots. Longitudinal profile shall be tested by a 3 m straight edge in a st retch of atleast 9 m length. Transverse profile viz. camber/crossfall/ super ele vation shall be tested using camber templates at two or three locations for each 100 m length. Temperature measurement shall be done by metallic contact thermom eter with digital display. (ii) (iii) (iv) 3

1. Introduction 3.3 Simple/Hand-Feel Tests For monitoring the quality of work, generally it may not be possible to carry ou t the detailed quality control tests and therefore, for the purpose of quality m onitoring simple/handfeel tests can be performed. Normally various simple tests have been used by the experienced practising engineers in the field to make a qu ick assessment of the quality of the product. However, these procedures have not been standardized and involve human judgement. Therefore, these tests which pro vide useful guidance for supervisory officers during inspections, should by no m eans be used as a replacement of the specified quality control tests. Some simpl e handfeel tests which are useful for quality monitoring are given in Appendix I . 4. COVERAGE OF THE HANDBOOK The Handbook is divided into two volumes: Volume I: Quality Management System an d Quality Control Requirements Volume II: Equipment and Test Procedures The Volu me I covers quality management system and describes in detail quality control of works by Field Units and supervisory staff and quality monitoring by National/S tate Quality monitors for various activities of construction and maintenance of rural roads. The Sections in this Volume correspond to the Sections of the Speci fications for Rural Roads of the Ministry of Rural Development, Government of In dia. The Volume II covers laboratory set up, equipment and test procedures for v arious quality control tests. 5. Flow Chart A typical flow chart for quality assurance checks during the construction of rur al roads is given as an illustration in Figure 1.1. 4

Quality Assurance Handbook for Rural Roads Earthwork Granular sub-base eg Road Component Water Bound Macadam Premix carpet Road Signs Borrow area (Earthwork) Material tests eg Select Source of Material Select alternative source Not Possible Possible Not Acceptable Quarry (Aggregates) Supplier (Bitumen, cement, steel & paint) Gradation, size At terberg limits Specific gravity Aggregate impact value Flakiness index Soundness Water absorption Stripping value Density, CBR Undertake cost efficient steps to improve quality Carry out tests on quality of materials (as per procedure) Acceptable Convey app roval to go ahead eg Sampling Frequency Acceptance criteria Trials, if necessary Organise resources M en Materials Machinery (Workmanship) Workmanship tests Yes Undertake construction operations, layer by layer (as per Specifications) Remedy the deficiency Carry out tests for each layer (as per procedure) Not acceptable Acceptable eg Line, level, grade Cross section, camber Thickness Compaction density CC Strengt h No Reject the work Go to next layer or next component All works Remedy the deficiency Deficiency completed Inspection No deficiency Open to traffic Sampling Frequency Acceptance criteria Figure 1.1: Typical Flow Chart for Quality in Road s shall maintain proper quality control records in dition to the quality control exercised by the PIU l quality monitoring checks will be carried out by 5 Works Notes: 1. 2. Field unit the prescribed formats. In ad as described above, additiona second and third tiers.

For soil and aggregates

Quality Assurance Handbook for Rural Roads CHAPTER 2 QUALITY MANAGEMENT SYSTEM 1. INTRODUCTION Rural Road Projects are often very small in size and widely scattered in remote areas with very limited basic facilities like ready availability of electric sup ply, drinking water and road access to heavy plant/ equipment etc. The material specifications generally incorporate the use of a wide variety of low cost local ly available materials. The speed of construction is relatively slow and the ava ilable resources as well as skills with small contractors are at a relatively lo wer level. It is, therefore, necessary that while developing a suitable Quality Management System for both construction and maintenance work, such constraints a re kept in view. The types of quality control tests and their frequency have als o to be judiciously selected so as to be achievable under the prevailing conditi ons. Keeping the above factors in mind, a three tier quality management system t ogether with a simplified practical approach to Quality Assurance in Rural Road works is prescribed as detailed in subsequent paragraphs. 2. THREE TIER SET UP FOR QUALITY MANAGEMENT SYSTEM The three tier quality management mechanism comprises: (a) (b) (c) First Tier: I n-house quality control by the executing agency Second Tier: Independent quality control set up of the State Rural Roads Development Agency. Third Tier: Nationa l Quality Monitoring system as operationalised by NRRDA for PMGSY. The second and third tier will not be connected with the Project Implementation Unit (PIU). 3. FIRST TIER 3.1 The PIU is envisaged as a first tier of quality management with the primary function of construction supervision and quality control. The quality management functions of the PIU shall include the following: (i) Preparation of realistic detailed project report (DPR) with adequate attention to investigations and preconstruction activities which are essential for proper design and estimation of the project following MoRD Specifications for Rural Roads, Rural Roads Manual an d other relevant IRC specifications. Preparation of bid documents and effective selection process for procurement of works, based on proven capacity and ability of the contractors. 7 (ii)

2. Quality Management System (iii) Ensuring that: (a) (b) (c) (d) Contractors have brought the necessary machinery and equipment to site. Field laboratory has been established. Key engineering pe rsonnel have been deployed by the Contractor and The work programme has been app roved. (iv) (v) Supervising Site Quality Control arrangements including materials and workmanshi p, primarily through testing as per provisions of the Quality Assurance Handbook . The following frequency of inspection visits to site by PIU staff is recommend ed while the work is in progress: (a) (b) (c) Junior Engineer Daily Assistant En gineer Twice a week Executive Engineer Once a week (vi) Taking timely action to ensure replacement of defective material and rectificati on of defective workmanship. 3.2 To ensure effective Quality Control on materials and workmanship, the proced ure described in para 3.1 of Chapter 1 shall be followed: 3.3 A monthly return o f the tests shall be submitted in the prescribed proforma by the AE to the EE in the first week of every month. The EE will review this return regularly to see that the Quality Control tests are being performed at the desired frequency and with the desired accuracy. The EE will also verify that the Non Conformance Repo rts (NCR) are being issued by the AE whenever nonconformance occurs and the Cont ractor is taking action promptly on the NCR. Payment to the Contractor shall be regulated by the EE as per the returns of the Quality Control tests. Any deviati on will be the personal responsibility of the EE. 3.4 The SE in charge of the ci rcle and the Chief Engineer having jurisdiction are responsible for the proper f unctioning of the PIU as part of their normal administrative duties. Their inspe ction and quality testing supervision will therefore be counted as part of effec tive supervision of the first tier of quality management (and not as a second ti er of quality management). The SE/CE shall: (i) During his visits to the work, o versee the operations of the quality control testing procedure and record his ob servations in the Quality Control Register. The SE/CE will also verify that the Non-Conformance Reports are issued in time and action is being taken by Contract or promptly. Prepare Inspection Reports which shall be sent to the PIU for takin g remedial action. (ii) The State Govt. /State Rural Roads Development Agency shall prescribe frequency of inspections by various officers and formats for furnishing inspection reports by SE/CE. 4. SECOND TIER 4.1 The first tier of quality management has the primary function of quality con trol through enforcement of technical standards and quality control requirements through regular testing, close 8

Quality Assurance Handbook for Rural Roads supervision and inspection. Function of the second tier of independent quality m anagement is to ensure that the Quality Management System at the site is functio ning satisfactorily and suggest possible improvements where required. For this, they may be required to carry out and report: (a) (b) Independent quality tests to verify that the quality management system achieving its intended objectives. Systemic flaws in the quality control process and action to improve the process. 4.2 The role of second tier in monitoring the quality of the work is of crucial importance during construction stage and therefore the State Quality Monitors ar e required to carry out inspections at appropriate stages of work under progress . 4.3 The independent Quality Management Division of the executing agency may fu nction as the second tier. The State Rural Roads Development Agency will frame s uitable guidelines for proper functioning of second tier. 5. THIRD TIER The National Rural Roads Development Agency shall prescribe the guidelines for t he third tier from time to time. The objective of this third tier of quality mec hanism is to monitor the quality of road works executed by the States with a vie w to ensuring that the road works under the programme conform to standards and t o see whether the quality management mechanism in the State is effective. The ro le of this tier is to provide guidance to State implementation machinery and the field engineers rather than fault finding. As such, the shortcomings are identifi ed by the third tier and a feedback is provided to the States for improvement. 6. QUALITY CONTROL The requirement of a quality control organization will vary for different projec ts depending on departmental set-up and also size of the project. The minimum su ggested organization of quality control laboratory set-up at Field, District and Central level shall be as follows: 6.1 Field Laboratory The Contractor shall be responsible to set up and maintain an adequately equippe d Field Laboratory for routine tests for quality control required to be conducte d on a day to day basis. The Field Laboratory will have normally those test equi pment that do not require electric power supply and are relevant to the project specifications. Field Laboratory will be manned by suitably trained personnel in material testing and quality control works. 6.2 District Laboratory The tests which are required to be done during the project preparation stage suc h as those pertaining to suitability of construction materials, selection of qua rries etc. to be carried out before incorporation in the work as part of quality control or the tests which cannot be carried out in the Field Laboratory shall be conducted in the District Laboratory. The District Laboratory will cover the testing requirements for the entire District. Such a Laboratory shall be equippe d with facilities for most of the tests, including those required for DPR prepar ation. 9

2. Quality Management System A typical set up of a District Laboratory is given in fig. 2.1. Fig. 2.1 Typical set up of a District Laboratory 6.3 Central Laboratory Tests requiring high level of skills and sophisticated equipment as also for the other quality tests will be carried out at the Central Laboratory under the con trol of the Chief Engineer or In-charge Quality Control, State Rural Roads Devel opment Agency preferably at the State Headquarters. Any special or sophisticated tests, for which the necessary equipment and expertise are not available in the Central Laboratory, shall be outsourced, to approved National Accreditation Boa rd for Laboratories (NABL) accredited Test houses or Higher Technical (academic) Institutes or Research Laboratories. 7. SPECIFICATIONS AND CODES OF PRACTICE The specifications and codes of practice laid down by Ministry of Rural Developm ent, Indian Roads Congress and Bureau of Indian Standards are required to be fol lowed in construction of rural roads. The list of IRC Publications and List of M ORD and MORTH Publications is given at Appendix 3 and 4 respectively in Volume I and list of Indian Standards in Volume II at Appendix-1. 8. LABORATORY AND EQUIPMENT The equipment requirement for quality control tests for Field, District and Cent ral Laboratories are given in Section100 of Volume II. 10

Quality Assurance Handbook for Rural Roads CHAPTER 3 QALITY CONTROL OF WORKS SECTION 100 GENERAL 11

Quality Assurance Handbook for Rural Roads 105. CONSTRUCTION EQUIPMENT 1. For ensuring quality of work, an appropriate technology must be adopted. In t he context of rural roads, an appropriate technology implies an optimum blend of manual methods and mechanical equipment of adequate capacity which may also inv olve use of agricultural implements towed by tractor. Guidelines for choosing ap propriate equipment and technology for rural roads are given at Appendix-2. Ensu re that the equipment deployed is appropriate to the work and is properly operat ed and maintained. Arrange a trial run of the equipment before commencement of t he work. Ensure that no equipment is deployed at or removed from the site of wor k without prior approval of the employer. 2. 3. 4. 108. SETTING OUT A 1. Methodology Establish working bench marks at 250 m intervals and also at or near all drainag e structures and bridges on the road. All the bench marks should be tied with th e Reference Bench Mark in the area. In hilly areas, reference pillars handed ove r by the Engineer to the Contractor shall work as bench marks. Establish centre line of the carriageway and have it referenced by marker pegs and chainage board s set near the road land boundary at 50 m intervals for roads in plain and rolli ng terrains. For roads in hilly areas and on curves in plains, the interval of r eference pegs should be 20 m. For sharp curves, the interval should be 10 m and for hair pin bends the interval should be 5 m. For hill roads, the valley side t op edge of reference pillar shall be at ground level. The top levels of referenc e pillars should be tied with the level of Bench Mark adopted in the DPR. For hi ll roads, back cutting line shall be demarcated on the hill face by digging, tak ing into account the designed slope of hill cutting. Back pillars showing the re quisite information should be located at about 1.5 m away (towards hill side) fr om the back cutting line. Alternatively, back pillars can also be fixed on any p ermanent existing structures in difficult terrain. Check distance of back cuttin g line from reference pegs. Prepare a schedule of reference dimensions and maint ain the markers/ reference pillars until the works reach finished formation leve l and are accepted by the Engineer. Verify the dimensions and levels, shown on t he drawings or mentioned in contract documents, on the site and inform the Engin eer of any apparent errors or discrepancies. The lines and levels of formation, side slopes, drainage works, carriageway and shoulders should be carefully set o ut and frequently checked, care being taken to ensure that correct gradients and cross-sections are obtained everywhere. The plan dimensions of the foundations for culverts shall be set out at the bottom of foundation trench and checked wit h reference to original line of reference and axis. 13 2. 3. 4. 5. 6. 7. 8. 9.

3. Section-100 B 1. Quality Control Requirements Horizontal Alignment Horizontal alignment shall be reckoned with respect to the centre line of the carriageway as shown on the drawings. 2. 20 mm

Edges of carriageway Edges of roadway and / lower layers of pavement C 1. 2. 3. 4. 5. Dos and Donts Dos Check whether Reference benchmark is indicated on the drawings. Regularly che ck the working bench marks as work proceeds. Arrange safety of survey bench mark s, monuments, beacons etc. and reference pillars in hilly areas Check layout of Curves. Supply a copy of survey file containing the necessary data to the Engine er for his record. 1. Donts Dont commence work until the initial center line is es tablished by marker pegs and cross sections at specified intervals have been app roved by the Engineer. Do not remove reference pegs, pillars or markers without approval of the Engineer. 2. 109 & 110. PUBLIC UTILITIES AND ENVIRONMENT A 1. 2. 3. 4. 5. 6. Methodology Verify at site, public utilities like water pipes, sewers, electric lines, telep hone cables etc. included in contract documents. Arrange for regular meetings wi th various agencies owning utilities at the commencement and throughout the dura tion of the works. Temporarily support the utilities affected by the works. Assi st agencies owning the utilities in carrying out the works with approval of the Engineer. Abide by all laws, rules and regulations in force governing pollution and environment and wild life protection, applicable in the area. Obtain approva l of concerned authorities for obtaining materials from quarries and for locatin g plant and equipment. 14

The permitted tolerances are given in Table 108.1 TABLE 108.1: PERMITTED TOLERANCES Alignment Plain and Rolling Terrain m Hilly Terrain 30 mm 50 mm

30 m

Quality Assurance Handbook for Rural Roads B 1. 2. Dos and Donts Dos Donts Protect utility services during construction period. Control soil erosion, sedim entation and reduce levels of noise, vibration, dust and emissions from construc tion plant and equipment. Keep the roadside and surroundings clean and free from dust, mud or other extraneous material. Cut material should be disposed of at p redetermined dumping places. 1. 2. 3. 4. Do not carry out any clearance or alterations to any utility unless especially o rdered by the Engineer. Do not cause any damage to public utilities. Do not poll ute natural water-courses, pools, tanks and reservoirs. Do not use hazardous mat erials without providing protective clothing, masks, shoes etc. to the workers. 3. 4. 114. METHODOLOGY AND SEQUENCE OF WORK A. 1. Methodology Ensure that a detailed construction methodology is submitted by the Contractor p rior to start of the construction activities in accordance with the Contract Agr eement. The construction methodology will include:Mechanical Equipment proposed to be used. Sequence of various activities and schedule from start to end of the project. (i) (ii) Programme relating to pavement and shoulder construction shall be an integrated activity to be done simultaneously in a coordinated manner. The methodology and sequence shall be so planned as to provide proper safety, drainage and smooth mo vement of traffic. 15

Quality Assurance Handbook for Rural Roads SECTION 200 SITE CLEARANCE 17

Quality Assurance Handbook for Rural Roads 201 & 202. SITE CLEARANCE A 1. Methodology The road land should be cleared of all materials unsuitable for the work by cutt ing, trimming, removing and disposing of all materials, such as trees, bushes, s hrubs, stumps, roots, grass, weeds, top organic soil not exceeding 150 mm in thi ckness and rubbish, etc. This should be carried out well in advance of earthwork operations. The top soil removed during clearing and grubbing of site, if suita ble for re-use shall be transported, conserved and stacked for re-use. All trees , stumps, etc. falling within the excavation and embankment lines should be cut to such depth below ground level that in no case these fall within 500 mm of the subgrade. Beyond these limits, they need to be cut down to 500 mm below ground level. Excavations below the ground level arising out of removal of trees, stump s, etc., should be filled in layers with suitable material and compacted to the specified density given by the Engineer. Measurement of trees having girth more than 300 mm should be done as per sizes given in the Bill of Quantities (BOQ). A nt-hills both above and below the ground shall be removed by excavating to a sui table depth as directed by the Engineer. Cavities in the ground after removal of ant-hills shall be filled with appropriate material and properly compacted to t he specified density. Existing structures which are within the road land and des ignated for removal should be dismantled carefully and the resulting materials s o removed as not to cause any damage to the serviceable materials to be salvaged , the parts of the structure to be retained and any other adjoining properties a nd utilities. Holes and depressions caused by dismantling operations or caused b y rats etc. shall be backfilled with approved material and compacted to the requ ired density. 2. 3. 4. 5. 6. 7. 8. B. Dos and Donts Dos Donts 1. 2. Take appropriate measures against soil erosion and water pollution. Obtain prior permission of the competent authority for removing/ disturbing any existing uti lities etc. required, if any. Conserve top-soil for re-use where suitable. 1. Do not forget to: (a) backfill the pits resulting from uprooting trees, stumps a nd removal of anthills etc. with suitable material and compact thoroughly. Immed iately remove unsuitable materials obtained from clearing the site. (b) 2. 3.

Do not disturb existing poles, fences, signs, monuments, buildings, pipelines, s ewers, trees etc. which do not interfere with the work and are to be retained. D o not damage parts of existing structures to be retained while dismantling porti ons interfering with the work. 3. 19

Quality Assurance Handbook for Rural Roads SECTION 300 EARTH WORK 21

Quality Assurance Handbook for Rural Roads 301. EMBANKMENT CONSTRUCTION A 1 Methodology Obtain materials (soil) for embankment from approved sources. Preference should be given to materials that are suitable and become available from nearby road ex cavation. (Refer Section B for quality control requirements). After clearing the site, mark the limits of embankment by fixing batter pegs and marking toe lines on both sides at regular intervals as guides. The embankment shall be built suf ficiently wider (about 300 mm on either side of Roadway) than the specified form ation width so that surplus material at the edges may be trimmed to ensure prope r compaction of the edges and side slopes. Remove stagnant water, if any, from t he foundation of the embankment. Where the available embankment materials (Soil) are not conducive to plant growth, topsoil from areas of cutting and areas to b e covered by embankment should be stripped to specified depth not exceeding 150 mm and stored for covering slopes, and other disturbed areas where re-vegetation is required. After removing the top soil/ unsuitable material, foundation for e mbankment construction shall be prepared as follows: (a) For embankment less tha n 1.0 m high over natural ground, the ground surface should be loosened up to a minimum depth of 150 mm by ploughing or scarifying and compacted to the specifie d density as per Para B5. For embankment less than 0.5 m height over an existing black-topped or gravel road, the black-topping shall be removed and the pavemen t/ gravel road should be scarified to a minimum depth of 150 mm. All particles s hall be reduced to a maximum size of 75 mm and compacted according to Para B5. I f the granular/ black topped surface lies within 0.50 m - 1 m of the new sub-gra de level, the same should be scarified to a depth of at least 50 mm for achievin g bond between old and new material. If the existing surface is of cement concre te type and lies within 1 m of the new sub-grade level, the same shall be remove d completely. For embankment over ground not capable of supporting equipment, su ccessive loads of embankment materials should be spread in a uniformly distribut ed layer of adequate thickness to support the equipment and to construct the low er portion of the embankment. For embankment construction on existing slope stee per than 1 Vertical: 4 Horizontal, horizontal benches should be cut in the exist ing slope to a sufficient width to accommodate placement and compaction equipmen t. 2 3 4 5 (b) (c) (d) (e) (f) 6 7 The size of the coarse material in the mixture of earth used for embankment cons truction should ordinarily not exceed 75 mm. The soil should be spread over the entire width of the embankment in layers not exceeding 150 mm compacted thicknes s. The clods should be broken to less than 75 mm size. Each layer at a moisture content within ( ) 2 % of the optimum moisture content, should be thoroughly compa

cted 23

3. Section-300 by roller, to the specified requirements as per Para B.5 and finished parallel t o the final crosssection of the embankment. (Compacted layer thickness can be in creased upto 200 mm if heavy vibratory rollers are used). 8 Compaction of soil s hould be done at OMC with a tolerance limit of ( ) 2 percent. If the moisture cont ent of soil is outside these limits, it shall be made good by adding water or dr ying by aeration and exposure to sun till the moisture content is acceptable for compaction. Each layer should be compacted to at least 97 percent of the Standa rd Proctor Density. The top 300 mm of the embankment constituting the sub grade should be compacted to 100 percent Standard Proctor Density according to Para B. 5. Ensure that longitudinal and cross profiles should be in conformity with the approved drawings. Approval of the Engineer should be obtained for each finished layer. Subsequent layers shall be placed only after the finished layer has been tested and accepted by Engineer. (Such an approval would require surface level and compaction control tests). When an existing embankment and/ or sub-grade is to be widened and its slopes are steeper than 1 vertical to 4 horizontal, contin uous horizontal benches, each at least 300 mm wide, should be cut into the old s lope for ensuring adequate bond with the fresh embankment/ sub-grade material to be added. When the width of the widened portions is insufficient to permit the use of conventional rollers, compaction shall be carried out with the help of sm all vibratory rollers/ plate compacters/ power rammers or any other equipment ap proved by the Engineer. The filling around culverts and bridges, for forming app roaches up to a distance of twice the height of the road from the back of abutme nt should be done with granular materials and should not be placed until the con crete or masonry has been in position for 14 days. Approval for the sequence of work and equipment should be obtained from the Engineer before taking up the wor k. 9 10 11 12 13 14 B 1. (a.) Quality Control Requirements Materials The material used in embankment, sub-grade, shoulders, etc. shall be s oil, moorum, gravel, a mixture of these or other material approved by the Engine er. It shall be free from logs, stumps, roots, rubbish, etc. The following types of material shall be considered unsuitable: (i) (ii) (iii) (iv) (v) (vi) Materi al from swamps, marshes and bogs Peat, log, stump and perishable material; soil classified as OL, OI, OH or Pt as per IS:1498. Materials susceptible to spontane ous combustion Clay having liquid limit exceeding 70 and plasticity index exceed ing 45 Material with salts resulting in leaching action e.g. sodic soils (pH > 8.5) Exp ansive clay with free swelling index exceeding 50 per cent 24

Quality Assurance Handbook for Rural Roads (vii) Materials in a frozen condition (viii) Fill materials with a soluble sulph ate content exceeding 1.9 gm of sulphate, (expressed as SO3) per litre, if depos ited within 500 mm or other distance described in the Contract, of concrete, cem ent bound materials or other cementitious materials forming part of permanent wo rks (ix) Material with a total sulphate content (expressed as SO3) exceeding 0.5 per cent by mass, if deposited within 500 mm or other distance described in the Contract, of metallic items forming part of permanent works (b) (c) The size of coarse material shall not ordinarily exceed 75 mm when placed in emb ankment and 50 mm when placed in sub-grade. Only the materials satisfying the de nsity requirements given in Table 301.1 should be used for the embankment. TABLE 301.1: MINIMUM DENSITY REQUIREMENT FOR SUITABILITY OF EMBANKMENT/SUB-GRADE MATERIALS Type of Work Max. laboratory dry unit weight IS:2720, Part 7 Not less than 14.4 kN/m3 Not less than 15.2 kN/m3 Not less than 15.2 kN/m3 (a) Embankment not subject to floodingheight upto 3 m height more than 3 m Embankmen t subject to flooding (b) 2. Horizontal Alignment The alignment shall be reckoned with respect to the centre line of the carriagew ay as shown on the drawings. The edges of the roadway as constructed shall be wi thin the following tolerances indicated in Table 301.2: TABLE 301.2: PERMITTED TOLERANCES FOR EDGES OF CARRIAGEWAY AND ROADWAY Descripti on Edges of carriageway Edges of roadway and lower layers of pavement Plain and Rolling Terrains ( ) 20mm ( ) 30mm Hilly Terrain ( ) 30mm ( ) 50mm 3. Surface Levels The permitted tolerance in surface level for sub-grade will be +2 0 mm and (-) 25 mm. 4. Surface Regularity The maximum allowable difference between the road surface and underside of a 3 m straight edge shall be 20 mm for the longitudinal profile an d 15 mm for the cross profile. 25

3. Section-300 5. Degree of Compaction The embankment shall be compacted to satisfy the density re quirements given in Table 301.3. TABLE 301.3: COMPACTION REQUIREMENTS FOR EMBANKMENT/SUB-GRADE/EXPANSIVE CLAYS Ty pe of work Relative Compaction as percentage of maximum laboratory dry density N ot less than 97 percent of Standard Proctor Density as per IS:2720 (Part 7) Not less than 100 percent of Standard Proctor Density as per IS:2720 (Part 7) Embankment Sub-grade (Top 300 mm of embankment and shoulders) Expansive clays i) Sub-grade and 500 mm portion just below the sub-grade. Not al lowed Not less than 90 percent of Standard Proctor Density as per IS:2720 (Part 7) ii) Remaining portion of Embankment 6. 6.1 Quality Control Tests and their Frequency Tests Prior to Construction The qualit y control tests to be carried out prior to construction and their frequency shal l be as given in Table 301.4. Table 301.4: QUALITY CONTROL TESTS AND THEIR FREQUENCY FOR BORROW MATERIAL, EART HWORK FOR EMBANKMENT AND FOR SUBGRADE Type of Test Frequency A. Earthwork for Embankment 1. Soil Classification as per IS:1498 i) Sieve Analysis (Wet Sieve Analysis except for cohesionless soils) ii) LL, PL and PI 2. Standar d Proctor Compaction Test (IS:2720 Part 7). Test results to ascertain Dry Densit y-Moisture Content Relationship. 3. Free Swell Index Test (IS:2720 Part 40) (a). 4. Deleterious Content(b) (i) Organic matter content by loss-on-Ignition method or as per IS 2720-Part 22. -do-doOne test from each source for one km or part t hereof. -do-do(ii) Total soluble sulphate content (IS 2720-Part 27) where suspected on past ex perience. This can be easily confirmed by a quick test using barium chloride. 26

Quality Assurance Handbook for Rural Roads B. Earthwork for Subgrade (Cutting or Filling) (i) Tests at 1 to 4, under A above. (In case the soil for embankment meets the prescribed requirements for the Subgr ade, the above four tests need not be repeated.) One test for each km length or part thereof, from each source.(c) One test for each km: this will comprise test ing of 3 specimens and the CBR value will be reported as average of the three te st values. (ii) CBR Test (IS:2720 Part 16) soaked/unsoaked as specified. Notes: (a) (b) Test for free swell index to be conducted only in case of expansi ve soils. Presence of deleterious content can be initially detected through colo ur, odour and existence of any organic matter. Where such observations justify n eed for further testing, simple tests at (i) and (ii) above shall be carried out . Detailed testing as per IS:2720Part 22 and Part 27 shall be done only after pr esence of deleterious content is confirmed by simple tests. For hill roads, the frequency of tests may be increased depending upon the variability of the strata met. (c) 6.2 Tests During Construction The quality control tests to be carried out during con struction and their frequency shall be as given in Table 301.5. TABLE 301.5: FIELD QUALITY CONTROL TESTS DURING CONSTRUCTION Type of Test 1. Pla cement Moisture (IS:2720 Part 2) Any of the rapid test methods for determination of moisture content can beused: Insitu Density Measurements (IS:2720 Part 28) ( Each layer) Frequency At least 3 tests daily (well spread over the days work) 2. -do(i) Average of 3 tests results shall not be less than the specified degree of compaction. (ii) Individual test values of the degree of compaction obtained sh all not be less than 1% of the specified value of degree of compaction. (For exa mple, for the specified 100% Proctordensity, the individual test value shall not be less than 99% of Proctor density and the average of the three (or more) test s carried out in a day shall not be less than 100% Proctor density). At random 3. Thickness of subgrade layer. 27

3. Section-300 6.3 Quality Control Checks by AE/EE TABLE 301.6 : QUALITY CONTROL CHECKS BY AE/EE Stage Test (i) Degree of Compactio n (IS:2720 Part 28) (ii) Surface Regularity and Transverse Profile Frequency Min imum 3 tests for each km length or part thereof; allowable tolerance in test val ues as per para 6.2. One of the tests shall be carried out at a depth of 150 mm from the top. Random Checking Designation of Inspecting Officer AE A. Top of the Embankment (Before placing Subgrade Layer) AE B. Finished Subgrade (i) Degree of compaction (IS:2720 Part 28) (a) One test for each 300 m length or part thereof. (b) One test for each 1000 m length or part thereof. One of the tests shall be carried out at a depth of 150 mm from the top. AE EE (ii) Surface Regularity and Transverse Profile/camber/ crossfall and superelevat ion Random Checking EE C. 1. Dos and Donts Dos Donts Discourage borrow pits along the road; where permitted, ridges of minimum 8 m wi dth should be left at intervals not exceeding 300 m. Small drains should be cut through the ridges to facilitate drainage. The depth of borrow pits should be so regulated that their bottom does not cut an imaginary line having a slope of 1 vertical to 4 horizontal projected from the edge of the final section of the ban k, the maximum depth in any case being limited to 1.0 m. Do maintain a camber/ c ross fall of 4 percent during construction for effective drainage and prevention of ponding of water. The area of the embankment foundation should be kept dry. Test the material (soil) for its suitability for use in the embankment at least seven days before commencement of earthwork. Tests should include soil. classifi cation test data and data regarding maximum dry density, OMC, and CBR (soaked an d unsoaked). For widening of existing embankment start earth work from toe line. 1. Do not allow borrow pits within a distance equal to the height of the embankment subject to a minimum of 1.5 m from the toe of the road embankment. Do not allow borrow pits within 800 m of towns or villages. Do not use unsuitable material f or embankment construction (Refer para B.1). Do not allow construction or other vehicular traffic over the prepared surface of embankment/ sub-grade. Do not pla

ce successive layers of embankment until the previous layer has been thoroughly compacted and duly approved by Engineer. Do not allow any damage to works, crops or other property while discharging stagnant water found in embankment foundati on. Do not allow dumping of earth from top to widen an existing embankment. 2. 3. 4. 5. 2. 3. 4. 6. 7. 5. 28

Quality Assurance Handbook for Rural Roads 302. EARTHWORK IN CUTTING A. 1. Methodology After site clearance, the limits of excavation should be set out true to lines, curves, slopes, grades and cross-sections as shown on the drawings by constructi ng reference pillars, back cutting lines, reference lines (1.5 m away from forma tion lines on hill and valley sides) If directed, the top soil shall be stripped to specified depths and stockpiled for reuse, as detailed in sub-section 301. E xcavation shall be done manually or mechanically using dozers. After excavation, the sides of excavated area should be trimmed and the area contoured to minimis e erosion and ponding, allowing natural drainage to take place. Cross drainage w orks like scuppers or small culverts 1 to 2 m span and side drains, shall be so constructed along the formation cutting work, as to have least interference with the existing drainage. The cut formation, which will serve as sub-grade, should be checked for its field density and if the field dry density of the material i n the top 300 mm portion is less than 100 per cent of maximum Proctor density, t he formation material shall be loosened to a depth of 500 mm and compacted in la yers to 100 per cent Standard Proctor Density (IS:2720-Part 7). In hilly areas, cutting should be done from top to bottom. Special attention should also be paid to side slopes and side drains in cutting. Rock when encountered in road excava tion shall be removed upto the formation level. Where unstable shales or other u nsuitable materials are encountered at the formation level, these shall be excav ated to the extent of 500 mm below the formation level. In rocky formation, the surface irregularities shall be corrected with granular base material to achieve the specified profile and levels. Where blasting is involved for rock cutting, guidelines given in sub-section 304 shall be followed. Excavation in marshes sha ll begin at one end and proceed in one direction across the entire marsh immedia tely ahead of backfilling to ensure complete removal or displacement of muck. Fo r widening of existing pavement, the existing shoulders shall be removed to thei r full width and upto sub-grade level to enable proper compaction in the widened portions. 2. 3. 4. 5. 6. 7. 8. 9. 10. 11. B. 1. Quality Control Requirements Horizontal Alignment The horizontal alignment should be reckoned with respect to the centre line of the carriageway as shown on the drawings. The edges of the r oadway as constructed should be correct within a tolerance limit of ( ) 30 mm in p lain and rolling terrain and ( ) 50 mm in hilly terrain. 2. Finishing No point on the slopes shall vary from the designated slopes by more t han 150 mm measured at right angles to the slope (300 mm in case of rock excavat ion).

29

3. Section-300 3. Surface Levels The tolerance in surface level for sub-grade will be (+) 20 mm an d () 25 mm. 4. Surface Regularity The maximum allowable difference between the sub-grade surfac e and underside of a 3 m straight edge shall be 20 mm for the longitudinal profi le and 15 mm for the cross profile. 5. Quality Control Tests Subgrade material shall be tested as per tests given in Ta ble 301.4 (B). If the material in the subgrade has a density of less than 100% o f maximum dry density (IS:2720 Part 7), the same shall be loosened to a depth of 500 mm (depth could be reduced to 300 mm if insitu density is not less than 95% of maximum dry density) and compacted in layers to 100% of maximum dry density. The density of compaction shall be tested as per Table 301.5 and checked as per Table 301.6. C. 1. Dos and Donts Dos Donts Take precautions against soil erosion, water pollution, etc. and for preservatio n of existing trees, drains, sewers, pipes, conduits, poles or any other structu res. Remove water, if met during excavation, from springs, seepage or other caus es, by suitable diversions, pumping, or bailing out to keep the excavation dry. Rocks and boulders, which are likely to cause differential settlement should be removed to the extent of 500 mm below the formation level. Take precautions duri ng construction to ensure stability and safety of slopes. Near village settlemen ts, trenches and foundation pits should be securely fenced and provided with cau tion signs in the interest of public safety. Ensure that unsuitable and surplus material from cuttings is disposed of as directed by the Engineer. Ensure that p roper longitudinal gradients as per drawings have been achieved. 1. Do not remove the bench marks, reference lines, stakes etc. used for setting out of works without informing the Engineer. Do not let the loose material/ debris remain on the slopes of cutting/ along the road. Do not allow the rock to protru de above the formation level at any point. Do not stack stone boulders on embank ment to ensure free flow of traffic especially on hill roads. Do not throw the d ebris on the valley side to avoid damage to property/ environment. 2. 3. 4. 5. 2. 3. 4. 5. 6. 7.

303. SUBGRADE CONSTRUCTION The sub-grade is top 300 mm compacted layer in embankment or cutting just beneat h the pavement crust. The subgrade in embankment is compacted to a higher standa rd than the lower layers of the embankment. In cutting, the cut formation, which serves as the subgrade, is treated similarly to achieve the specified density t o provide a suitable foundation for the pavement. A 1. Methodology Setting out, dewatering, stripping of top-soil etc. for subgrade construction sh all be the same as for embankment construction described in sub-section 301. 30

Quality Assurance Handbook for Rural Roads 2. 3. 4. Ensure that the soil for subgrade meets the specified requirements in terms of p hysical properties and the specified CBR value for pavement design. Compact each layer of the material in the subgrade at OMC ( ) 2% to at least 100% of Maximum D ry Density as per IS:2720 (Part 7). If the difference between the subgrade level (top of the sub-grade on which the pavement rests) and ground level is less tha n 300 mm and the ground does not have the needed 100% relative compaction with r espect to IS:2720 (Part-7), loosen the ground upto a level 300 mm below the subg rade level, correct moisture content to OMC ( ) 2% and compact in layers to 100% o f the maximum dry density as per IS:2720 (Part 7). If the subgrade soil does not possess the requisite engineering properties like highly plastic black cotton s oil and other weak soils yielding very low soaked CBR values, the same should be improved in strength (CBR) and workability by treatment with additives like lim e/cement etc. as described in sub-sections 403 and 404 or by mechanical stabiliz ation. In conditions where salt concentration is in excess of 0.2%, a capillary cut-off of coarse sand should be provided below the subgrade as shown in the dra wings to check the upward movement of moisture from below. For a road in cutting , prepare the subgrade in accordance with subsection 302 to receive a subbase co urse. Ensure that the subgrade is compacted and finished to the design strength consistent with other physical requirements. Maintain the surface of subgrade, a t all times during construction, at such a cross fall as will shed water and pre vent ponding. 5. 6. 7. 8. 9. B. 1. Quality Control Requirements Materials (i) The material used for subgrades shall be soil, moorum, gravel, a m ixture of these or any other approved material. Material considered unsuitable f or embankment construction as per subsection 301 shall not be used for sub-grade . The material for subgrade shall be non-expansive in nature. Where an expansive clay with acceptable free swelling index value is used as a fill material in emba nkment, the sub-grade and top 500 mm portion of the embankment just below the su b-grade shall be non-expansive in nature. Any fill material which yields a maxim um dry laboratory unit weight of less than 16.5 kN/ m3 determined as per IS:2720 (Part 7) shall be considered unsuitable for use in subgrade. The size of coarse material in the soil shall ordinarily not exceed 50 mm when placed in the subgr ade. (ii) (iii) (iv) (v) 2. Surface Level The permissible tolerances in surface levels of subgrade shall be (+) 20 mm and (-) 25 mm. 31

3. Section-300 3. Surface Regularity The maximum allowable difference between the subgrade and und erside of a 3 m straight edge shall not exceed 20 mm for longitudinal profile an d 15 mm for cross profile. 4. Quality Control Tests 4.1 4.2 4.3 The Quality Control Tests on Earthwork for Sub grade (in cutting or filling) and their frequency, prior to construction, shall be as per Table 301.4 (B). The Field Quality Control tests during construction s hall be as per Table 301.5. The Quality Checks shall be as per Table 301.6 (B). C. 1. Dos and Donts Dos Donts Do ensure that borrow area material for use in subgrade satisfies the specified requirements and design CBR. Do ensure that all layers in sub-grade are compacte d to 100% Proctor Density as per IS: 2720 (Part 7). 1. Do not proceed with sub-grade work until the foundation for sub-grade has been d uly approved by the Engineer. Do not allow construction traffic or other vehicul ar traffic over the prepared surface of sub-grade. 2. 2. 304. ROCK CUTTING I Rock Excavation A 1. Methodology Guidelines on Blasting Operations Ensure that(i) all the statutory laws, regulat ions, rules, etc. pertaining to the acquisition, transport, storage, handling an d use of explosives are followed and information describing pertinent blasting m ethod and procedures is furnished by the Contractor prior to starting the work. Detailed safety aspects are given in Annex-300.2 of Specifications for Rural Roa ds. the magazine for the storage of explosive is built to the designs and specif ications of the Inspection General Explosives, Nagpur and located at the approve d site. no unauthorized person is admitted into the magazine. no match sticks or inflammable material shall be allowed in the magazine. all explosives are store d in a secure manner and such storage places shall be clearly marked. the blasti ng operations remain in the charge of competent and experienced supervisors and workmen who are thoroughly acquainted with the details of handling explosives an d blasting operations. (ii) (iii) (iv) (v) (vi) (vii) the blasting is carried out during fixed hours of the day, preferably duri ng the mid-day luncheon hour or at the close of the work.

32

Quality Assurance Handbook for Rural Roads (viii) all public utility companies having structures in proximity of the site o f work are notified sufficiently in advance of the blasting work. (ix) (x) (xi) for blasting work within 50 m of any railway track or structures, the concerned Railway Authority is notified sufficiently in advance of the blasting work. red danger flags are displayed prominently in all directions during the blasting ope rations. The flags are planted 200 m from the blasting site in all directions. s ufficient safety arrangements shall be made, including positioning of manpower a t proper locations to ensure that all persons including workmen are excluded fro m the flagged area at least 10 minutes before the firing. (xii) blasting is as light as possible, consistent with thorough breakage of mat erial. (xiii) when blasting is done with powder or dynamite, the procedure outli ned in Clause 304.2.4 of MoRD Specifications for Rural Roads is followed. (xiv) at a time, not more than 10 charges are prepared and fired. (xv) after blasting operations, all loose residual material below sub-grade is compacted and any mat erial removed from below sub-grade is replaced with suitable material. 2. 3. 4. In case of misfire, follow the procedure laid down in clause 304.2.5 of Specific ations for Rural Roads. Maintain a day-to-day account of the explosives in an ap proved register. Such account shall be open to inspection at all times. Sufficie nt arrangements should be made like posting of guards at proper locations so tha t no person enters the area of influence during the blasting operations. B. 1. 2. 3. 4. 5. Quality Control Requirements All the materials, tools and equipment used for blasting operations shall be of approved type. Excavation by blasting shall be to the lines indicated in drawing s, with the least disturbance to the adjacent material. The magazine shall have a lightning conductor. The fuse to be used in wet locations shall be sufficientl y water-resistant as to be unaffected when immersed in water for 30 minutes. The rate of burning of the fuse shall be uniform and definitely known to permit suc h a length being cut as will permit sufficient time to the firer to reach a safe point before explosion takes place. Detonators shall be capable of giving effec tive blasting of the explosives. The blasting powder, explosives, detonators, fu ses, etc. shall be fresh and not damaged due to dampness, moisture or any other cause. The charge holes shall be drilled to required depths and at suitable plac es. 33 6. 7. 8.

3. Section-300 C Dos and Donts Dos Donts 1. Provide information describing pertinent blasting procedures, and dimensions to Engineer prior to starting any phase of the operation, Display prominently the f ollowing information in the lobby of magazine: (a) A copy of the relevant rules regarding safe storage both in English and in the language with which the worker s concerned are familiar. A statement of up-to-date stock in the magazine. A cer tificate showing the latest date of testing of the lightning conductor. A notice that smoking is strictly prohibited. 1. 2. Do not perform blasting operation without written permission of Engineer. Do not store explosives closer than 300 m from the road or from any building or campin g area or place of human occupancy. Do not keep any damaged blasting powder, exp losives, detonators fuses etc. at site. Do not use any method of blasting which leads to overshooting. Do not undertake blasting after sunset. Do no expose dyna mite to the sun or allow it to get damp. Do not ram or pound the charge but pres s firmly into place. 2. 3. 4. 5. 6. 7. (b) (c) (d) 3. 4. 5. Do intimate the hours of blasting to the people in vicinity. Do drill the charge holes to required depths and at suitable places. Do ensure that the man-in-char ge counts the number of explosions and ensures that all the charges have explode d before allowing workmen back to the site. II Presplitting Rock Excavation Slopes A 1. Methodology Prepare a plan outlining the position of all drill holes, depth of drilling, typ e of explosives to be used, loading pattern and sequence of firing. Controlled b lasting shall begin with a short test section of a length approved by the Engine er. The test section shall be presplit, production drilled and blasted to excava te sufficient material for acceptance of the method. Remove all overburden soil and weathered rock along the top of the excavation for a distance of about 5 to 15 m beyond the drilling limits, or the end of the excavation, before drilling t he presplitting holes. Ensure that the slope holes for presplitting are drilled along the line of the planned slope within the specified tolerances. The drill h oles shall be not less than 60 mm or more than 70 mm in diameter. No hole shall deviate from the plane of the planned slope by more than 300 mm nor shall any ho le deviate from being parallel to an adjacent hole by more than two-thirds of th e planned horizontal spacing between holes. The length of presplit holes shall n ot exceed 900 mm on centres. The maximum diameter of explosives used in presplit

hole shall not be greater than one-half the diameter of the presplit hole. Ammo nium nitrate composition blasting agents shall not be permitted in presplitting operations. 34 2. 3. 4.

Quality Assurance Handbook for Rural Roads 5. Where stemming is required to achieve satisfactory presplit face, stemming mater ial shall be dry free-running passing 11.2 mm sieve and 90 percent of which is r etained on 2.80 mm sieve. Stemmed presplit holes shall be completely filled to t he collar. B 1. 2. 3. 4. 5. Quality Control Requirements Quality control requirements for rock cutting mentioned in Para IB above shall a pply. Drilling operations shall be controlled by the use of proper equipment and technique. Only standard cartridge explosives prepared and packaged by explosiv e manufacturing firms shall be used in pre split holes. The presplit face shall not deviate by more than 300 mm from the plane passing through adjacent holes. W hen completed, the average plane of the slope shall conform to the slopes indica ted on the drawings and at no point shall the completed slopes vary from the des ignated slopes by more than 300 mm as measured perpendicular to the plane of the slope. In no case shall any portion of the slope encroach on the side drains. 6. C Dos and Donts Dos and Donts for rock cutting mentioned in Para IC shall apply, in addition to th e following: Dos Donts 1. Ensure that drill holes are not less than 60 mm or more than 75 mm in diameter. 1. 2. Do not drill any portion of production hole within 2.5 m of a presplit plane. Do not allow any portion of the slope to encroach on the side drains. 306. FLYASH EMBANKMENT CONSTRUCTION A 1. 2. 3. 4. Methodology Preparation of foundation for embankment, setting out, dewatering, stripping of top-soil shall be as for Embankment Construction detailed in sub-section 301. Th e side soil cover, of required width shall be provided along with the flyash cor e and shall be simultaneously compacted as the embankment progresses upwards. Sp read fill material to specified width, grade and slope by mechanical means. For small works manual method may be used. Depth of loose layer shall vary from 100 mm to 400 mm depending upon the weight and type of roller used for compaction as indicated in Table 306.1. 35

3. Section-300 TABLE 306.1 THICKNESS OF LAYER FOR FLYASH EMBANKMENT CONSTRUCTION Thickness of L ayer (loose) in mm Not exceeding 200 Not exceeding 400 250 100 to 150 Weight of static roller used in kN 80 to 100 80 to 100 60 to 80 10 to 15 Weight of vibrato ry roller used in kN 5. Moisture content of fill material before commencement of compaction, shall be wi thin ( ) 2% of the optimum moisture content when determined as per IS:2720 (Part-7 ). Moisture content of the cover soil shall be maintained at OMC. If water is re quired to be added to the fill material, the same shall be sprinkled from a wate r bowser without flooding. The water shall be mixed thoroughly by blading, disci ng or harrowing. Compaction of flyash should start as early as possible after sp reading. Each layer of flyash shall be thoroughly compacted to the specified den sity. When vibratory roller is used for compaction, two passes without vibration followed by 5 to 8 passes with vibration shall normally be sufficient to compac t each layer. The compaction of flyash core and earth cover on the sides shall p roceed simultaneously. After construction, flyash embankment shall conform to th e following: (i) Minimum dry density after compaction as percentage of maximum d ry density determined as per IS 2720 (Part-7) (ii) Minimum dry density after com paction, when used in bridge abutments for embankment length equal to 1.5 times the height of the embankment, as percentage of maximum dry density determined as per IS 2720 (Part 7) 100% 98% 6. 7. 8. 9. 10. On the top of flyash embankment, at least 500 mm thick selected earth embankment shall be provided, out of which top 300 mm shall be sub-grade as per sub-sectio n 303. Following precautions should be taken while handling flyash: (i) (ii) (ii i) Flyash (Pond Ash) should be delivered to site in covered dumper trucks to min imize loss of moisture and dusting preferably during night. Stockpiling of flyas h at site should be avoided. If stockpiling at site cannot be avoided, dusting s hall be prevented by spraying water on stockpiles at regular intervals and by ke eping the stockpile covered with tarpaulin or a thin layer of material not subje ct to dusting e.g. soil or granular material. Traffic should be restricted in ar eas where flyash is temporarily stockpiled at site. (iv) 36

Quality Assurance Handbook for Rural Roads B. 1. Quality Control Requirements Material (a) Flyash (Pond Ash): Particle size analysis, Maximum Dry Density and Optimum Moisture Content as per IS:2720 (Part7), Graph of dry density plotted against moisture content for this test shall be submitted for approval of Engineer, before execution of work. (b) Soil: Soil for cover to the flyash embankment shall satisfy the requirements of a suit able material for embankment construction as per sub-section 301. (c) Sub-grade: Sub-grade shall conform to the requirements of sub-section 303. 2. Quality contr ol tests and their frequency shall be as indicated in Table 301.4 to 301.5. C Dos and Donts Dos Donts 1. 2. Check the placement moisture content of fill material which should be within ( ) 2 % of the OMC. Place subsequent layer only after finished layer has been tested f or density requirements and duly approved by the Engineer. Remove the material i n soft areas where requisite density requirements have not been achieved and rep lace the same by approved material, bring moisture content to permissible limits and recompact to the required density. Do transportation of fly-ash, normally a t night. 1. 2. 3. Do not allow addition of side cover subsequent to the construction of the flyash core. Do not allow traffic in areas where flyash is temporarily stockpiled and kept moist to avoid dusting. Do not allow construction traffic or other vehicula r traffic directly over the prepared surface of embankment/ sub-grade. 3. 4. 307. SURFACE DRAINS A. 1. 2. 3. Methodology Ensure that the surface drains/roadside ditches are provided strictly according to the Drainage Plan for the road. Excavate to the specified lines, grades, leve ls and dimensions. Remove all excavated material from the area adjoining the dra ins. If the excavated material is found suitable, utilize in embankment/sub-grad e construction, otherwise dispose of the material away from the road site. Ensur e that the excavated bed and sides of the drains are in conformity with the spec ified dimensions, levels and slopes. 4.

37

3. Section-300 5. Protect the surface of drains/roadside ditches with turf cover or other suitable lining as shown on the drawings. Consult the local agricultural department for selecting the appropriate species of grass/vegetation. Provide proper gradients and fix the invert for quick disposal of water to the outfall. For any stretch o f the rural road passing through a built-up area, ensure that any water coming f rom the adjacent habitations discharges only into the drain and is not allowed t o flow over the road surface. Any sharp edges, where cut/fill surfaces meet the ground level, should be rounded off to prevent erosion and promote turfing. Prov ide safe outlets to natural or artificial water courses. Provide catch water/int ercepting drains on hill slopes to intercept water from upper reaches, such drai ns to be provided over stable slopes only, outside any slide or unstable areas. 6. 7. 8. 9. 10. B. 1. Quality Control Requirements Materials (a) (b) (c) Where the soil is erodible, line the drain with random mas onry coursed with 1:5 cementsand mortar, as per subsection 700 or any other suit able material as shown on the drawings. The turf and variety of grass used for e rosion control must meet the specified requirements for use in the area. The mat erials used for other types of linings like brick masonry, stone masonry etc. mu st meet the relevant specifications given in Sections 600 & 700 respectively. 2. Dimensions The cross-section and side slopes should conform to the specified dim ensions. C. Dos and Donts Dos Donts 1. Ensure that the gradients are adequate for free flow of water to the outlet with out overflowing or ponding or undue siltation. Do ensure that grass, when used a s a lining forms a firm dense turf. Take special precautions in built-up areas t o make sure that water from any adjacent habitations does not flow over the road . Take care to see that a drain/roadside ditch is deep enough to drain the sub-b ase/base course. 1. 2. 3. 4. 5. Do not provide ordinarily side slopes steeper than 2:1 to avoid damage by erosio n. Do not leave any roadside ditch/drain unlined even if it be a grass lining. D o not leave any sharp edges within the cross-section to avoid damage by erosion. Do not allow the bottom of roadside ditch/drain to be below the bed of the cros s-stream at an outlet. Do not provide any catch water/ intercepting drain in any slide area/unstable area. 2. 3.

4. 38

Quality Assurance Handbook for Rural Roads SECTION 400 GRANULAR SUB-BASES, BASES & SURFACINGS 39

Quality Assurance Handbook for Rural Roads 401. GRANULAR SUB-BASE A 1. Methodology Obtain materials from approved sources. The material should be natural sand, moo rum, gravel, crushed stone, crushed slag, brick metal, kankar or a combination t hereof and it shall conform to grading and physical requirements indicated in Ta ble 401.1 Remove all vegetation and other extraneous material etc. from the subg rade already prepared, lightly sprinkle with water, if necessary, and roll with two passes of 80-100 kN road roller or any other suitable compactor/vibratory ot her? The sub-base material should be spread in layers not exceeding 100 mm compa cted thickness. If suitable vibratory rollers are available, the compacted thick ness of layer can be upto a maximum of 225 mm. When the sub-base material consis ts of a combination of materials, mixing shall be done mechanically by the mix-i n-place method, except for small sized jobs. Each layer shall be uniformly sprea d and thoroughly compacted. Spreading and compaction shall be carried out as per Clause 401.4.2 of the MORD Specifications. Compaction should be carried out at OMC, with a tolerance limit of ( ) two per cent. If the loose material is dry, as compared to OMC, water should be added by sprinkling and thoroughly mixed for u niform wetting. If it has more water than the optimum, it should be left exposed to sun and aeration till the moisture content is acceptable for compaction. Eac h layer should be compacted to 100 per cent maximum dry density as per standard Proctor Test-IS 2720 (Part 7). Approval of the Engineer should be obtained for e ach layer. Such an approval would require surface level and compaction control t ests. The earthen shoulders should be constructed simultaneously with the sub-ba se construction. 2. 3. 4. 5. 6. 7. 8. B 1. Quality Control Requirements Materials (i) Grading: The grading for granular sub-base (GSB) should conform to the requirements given in Table 401.1. TABLE 401.1: GRADING FOR GRANULAR SUB-BASE MATERIALS IS Sieve Designation Gradin g I Per cent by Weight Passing the IS Sieve Grading II 100 55-75 10-30 < 10 50-8 0 15-35 < 10 100 25-45 < 10 Grading III 75 mm 53 mm 26.5 mm 4.75 mm 0.075 mm (75 micron) 100 41

3. Section-400 (ii) (iii) (iv) Atterberg limits: the material passing 425 micron sieve when tested according to IS: 2720 (part 5) shall have liquid limit and plasticity index not more than 25 and 6 percent respectively. On clayey subgrades, the material passing IS Sieve 0.075 mm should not exceed 5 per cent. CBR value: The material with a minimum CB R value of 20 will be acceptable for granular sub-base. In case the subbase mate rial of the requisite CBR is not available within economical leads, the subbase material meeting any of the specified grading and other requirements with a soak ed CBR of not less than 15 can be permitted with the approval of the competent a uthority. The wet aggregate Impact Value (IS:5640) shall not exceed 50. (v) 2. Horizontal Alignment The edges of the sub-base shall be correct within a toleran ce limit of ( ) 30 mm in plain and rolling terrain and ( ) 50 mm for hilly terrain. 3. Surface Levels The tolerance in surface level for granular sub-base will be rest ricted to (+) 10 mm and (-) 20 mm. A grid of 10 m by 2.5 m may be formed to chec k the surface level. The cross profile should conform to the required camber. 4. Surface Regularity The maximum permitted difference between the sub-base and 3 m straight edge shall be 12 mm for longitudinal profile and 10 mm for cross profi le. The cross profile should conform to the required camber. 5. Degree of Compaction Density shall be 100 per cent of maximum dry density for th e material determined as per IS:2720, Part 7. 6. 6.1 Quality Control Tests Tests Prior to Construction (i) (ii) (iii) (iv) The qualit y control tests to be carried out prior to construction are indicated in Table 4 01.2. For existing approved sources, the test frequency shall be as indicated in Table 401.2. For new sources, test frequencies shall be increased to atleast th ree tests for each source (average of three tests). The samples shall be taken a t representative locations and at mean depth of proposed excavation. 42

Quality Assurance Handbook for Rural Roads TABLE 401.2 : QUALITY CONTROL TESTS PRIOR TO CONSTRUCTION Type of Test 1. Soil C lassification as per IS:1498. i) Wet Sieve Analysis, except for cohesionless soi ls ii) Liquid and Plastic Limits Combined Grading and Plasticity tests on materi als from different sources, mixed in the design proportions. This shall be done when materials from more than one source are combined. Proctor Compaction Test ( IS:2720 Part 7). Wet Aggregate Impact Value Test (IS:5640) where soft/marginal a ggregates are used e.g, Laterite, Kankar, Brick Ballast etc. CBR test (IS:2720 P art 16) on representative sample compacted at 100% Proctor dry density. Frequenc y Average of three tests from each source. 2. One test on the combined material for 500 m length of road or part thereof. 3. 4. One test on the material from each source or on the combined material, as the ca se may be. One test from each source identified by the Contractor. 5. One test per km length. (average of a set of three specimens). Note: Where materials from more than one source are to be combined in the desire d proportions, the tests at Sl. Nos. 2, 3 and 5 should be carried out on the com bined material. 6.2 Tests During Construction The field quality control tests during construction are indicated in Table 401.3 . TABLE 401.3 : QUALITY CONTROL TES